Electronic – use an axial inductor instead of a radial inductor

inductor

I want to build this Arduino DDS waveform generator. A Chebyshef lowpass filter with a cutoff at 12 KHz is required to filter out the 32KHz sampling noise.

Chebyshef lowpass filter

The inductors are 4.7mH. Now in the photo, one can see, what I assume are Magnetic Core 4.7MH Radial inductors.

Photo of Chebyshef lowpass filter

I would like to know if I can use Axial inductors instead?

Axial inductor

Will the performance of the Chebyshef filter be the same or degraded?

I have no implementation, or design, specific reason for doing this, apart from cost. This question is similar to Axial inductor vs winding inductor, but the application (frequency range) is different, Audio (KHz) rather than FM (MHz), so I was not sure if that would affect the answer.

Best Answer

The proposed ones will have a magnetic core only a different shape from the originals - there is no way that they can get 4.7mH without one. The original inductors are wound on what are called Drum cores. Your proposed one probably just has a cylindrical core. Since the magnetic field is not as well contained it will probably need more turns of finer wire which will increase its resistance and make it more lossy.

If the resistance of the proposed inductor is significantly different from the original the characteristics of the filter will be different.

Try simulating it in LTspice to compare the effect of any resistance change between the original and your proposed inductor.

I would expect it to perform adequately with the proposed parts.